/*
 * This is Melet, a salary slip designer. Feed it with data regarding to salary payment, prepare it for print through the graphical presentation, and you have it done.
 * Copyright (C) 2014, AFDiaX
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * This program is based on UMLet, a Free UML Tool for Fast UML Diagrams.
 * To contact the authors of UMLet visit https://code.google.com/p/umlet/people/list
 * To contact the authors of Melet visit https://gna.org/users/gabocze
 */
package com.baselet.gwt.client.view.panel.wrapper;

import org.vectomatic.dnd.DataTransferExt;
import org.vectomatic.dnd.DropPanel;
import org.vectomatic.file.FileList;

import com.baselet.gwt.client.view.interfaces.AutoresizeScrollDropTarget;
import com.google.gwt.event.dom.client.DomEvent;
import com.google.gwt.event.dom.client.DragEnterEvent;
import com.google.gwt.event.dom.client.DragEnterHandler;
import com.google.gwt.event.dom.client.DragLeaveEvent;
import com.google.gwt.event.dom.client.DragLeaveHandler;
import com.google.gwt.event.dom.client.DragOverEvent;
import com.google.gwt.event.dom.client.DragOverHandler;
import com.google.gwt.event.dom.client.DropEvent;
import com.google.gwt.event.dom.client.DropHandler;

public class FileDropPanel extends DropPanel {

	private final FileOpenHandler handler;

	public FileDropPanel(final AutoresizeScrollDropTarget diagram) {

		this.add(diagram);
		handler = new FileOpenHandler(diagram);

		addDragOverHandler(new DragOverHandler() {
			@Override
			public void onDragOver(DragOverEvent event) {
				avoidDefaultHandling(event);
			}
		});
		addDragEnterHandler(new DragEnterHandler() {
			@Override
			public void onDragEnter(DragEnterEvent event) {
				avoidDefaultHandling(event);
			}
		});
		addDragLeaveHandler(new DragLeaveHandler() {
			@Override
			public void onDragLeave(DragLeaveEvent event) {
				avoidDefaultHandling(event);
			}
		});
		addDropHandler(new DropHandler() {
			@Override
			public void onDrop(DropEvent event) {
				FileList files = event.getDataTransfer().<DataTransferExt> cast().getFiles();
				handler.processFiles(files);
				avoidDefaultHandling(event);
			}
		});

	}

	private void avoidDefaultHandling(DomEvent<?> event) {
		event.stopPropagation();
		event.preventDefault();
	}

}
